JPH06166366A - Hydraulic braking apparatus with skid control and traction slip control device - Google Patents

Abstract

PURPOSE: To generate pressure in a wheel brake promptly in a hydraulic brake system having a skid control device and a traction slip control device. CONSTITUTION: This hydraulic brake system 10 includes a brake pipe 17 extending between a master brake cylinder 15 and a wheel brake 18. The brake pipe 17 is disposed with a restricting part 30. The brake pipe 17 has the discharge pipe 46 for a high pressure pump 41, which provides a pressure medium during the traction slip control operation, opened between the restricting part 30 and a valve device 33 on the side of the wheel brake which modulates the brake pressure of the wheel brake 18. The restricting part 30 can be bypassed at the time of control start and cancellation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake of the type described in claim 1, and more particularly to an automotive hydraulic brake.

[0002]

2. Description of the Related Art When a shut-off valve arranged in a suction conduit takes a passing position only during traction slip control operation, and when braking by a driver is started, a pressure medium is short-termed by a pressure medium in a brake conduit. A brake device of the type that can bypass the valve device that modulates the pressure and flow into the wheel brake has already been proposed. When the controller of the brake device confirms the driver's desire to brake, the controller interrupts the traction slip control operation,
The shutoff valve in the brake conduit is switched to the pass position and the shutoff valve in the suction conduit is switched to the shut position. The pressure medium is now pumped through the brake conduit from the master brake cylinder into the wheel brakes. The braking device described above is equipped with a high-pressure pump for returning the pressure medium from the wheel brakes in skid control operation and for producing brake pressure in traction slip control operation. This high-pressure pump causes pulsations in the discharge flow. Therefore, behind this pump, a buffer chamber and a throttling point are arranged in the discharge conduit in order to avoid pulsations in the discharged pressure medium flow. However, this also reduces the discharge flow to some extent. However, in the traction slip control operation, it is desired to generate the brake pressure extremely quickly in the wheel brakes.

[0003]

SUMMARY OF THE INVENTION The object of the invention is to provide a brake system of the type mentioned at the outset in which the pressure buildup in the wheel brakes is very rapid.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic brake device having a skid control and a traction slip control device, wherein (a) a pedal-operable master brake cylinder (15) is connected to one brake circuit (I). The brake conduit (17) leads to one wheel brake (18), (b) the wheel brake (18) is assigned a valve device (33) for modulating the brake pressure, which valve device (33) Has an inlet valve (34) and an outlet valve (40) arranged in the braking device (17), and (c) a first shut-off valve on the master brake cylinder side in the brake conduit (17). (27) is placed,
The shutoff valve (27) is adapted to take the shutoff position (27b) during traction slip control operation,
(D) A first bypass conduit (2) in which the first shut-off valve (27) has a first check valve (29) for flowing pressure medium from the master brake cylinder (15) to the wheel brakes (18).
8) and the (e) inlet valve (34) is moved from the wheel brake (18) to the master brake cylinder (1).
5) is bypassed by a second bypass conduit (35) having a second check valve (36) for flowing the pressure medium to
(F) A high-pressure pump (41) is connected to the brake conduit (17) by a suction conduit (44) between the master brake cylinder (15) and the first shut-off valve (27) and the first shut-off valve (27). ) And an inlet valve (34) connected by a discharge conduit (46) to a brake conduit (17), and (g) a high pressure pump (41) on the suction side by a return conduit (39) to a valve device (33). ) Is connected to the outlet valve (40), and a second shutoff valve (50) is arranged in the (h) suction conduit (44), the shutoff valve (50) being in one shutoff position (50a). And (1) a flow position (50b), and (b) on the discharge side behind the high-pressure pump (41), a buffer chamber (47) and a throttling point (30) in the discharge conduit (46). Is installed, and the master brake is installed in the (nu) brake conduit (17). The a third check valve having from Linda (15) third check valve to flow of pressure medium towards the wheel brake (18) (49) (49) 3
Of the type in which the bypass conduit (48) is connected to the first shutoff valve (2).
7) and the connection of the discharge conduit (46) to the brake conduit (17), which is arranged in the brake conduit (17) and has at least the bypass conduit (35) of the inlet valve (34). Indirectly, the throttling part (30) and the first shutoff valve (2
7) is connected to the brake conduit (17),
(V) A third bypass conduit (48) on the one hand between the inlet valve (34) of the valve device (33) and the throttling point (30) and on the other hand at least indirectly with the throttling point (30). It was solved by being connected to the brake conduit (17) between the shut-off valve (27) and the shut-off valve (27).

[0005]

The effect of the invention is that the pressure medium delivered by the high-pressure pump is supplied to the brake conduit without overcoming the throttling points, so that the pressure builds up very quickly in the wheel brake during traction slip control operation. That is. On the other hand, the comfort of the brake device is maintained during skid control operation. This is because the throttling point in the brake conduit cooperates with the buffer chamber in the discharge conduit to avoid pulsation of the pressure medium flow during the pressure rise period. This has an advantageous effect on noise generation and feedback to the pedal. Furthermore, in spite of the throttling of the brake line, a delay-free start of braking and a rapid pressure drop when the brake is released are achieved. That is, the throttle portion in the brake conduit can be bypassed by the third bypass conduit when starting braking, and by the second bypass conduit when the brake is released.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The second and subsequent claims describe advantageous embodiments of the braking device according to the first claim.

An embodiment of the braking device according to claim 3 relates to a so-called K-distribution type braking circuit. That is, both wheel brakes of the brake circuit are assigned to the wheels on the diagonal. In this case, in the second wheel brake, only skid control operation is possible in addition to normal braking movement. The throttling point in the second brake conduit reduces the pressure increase rate of the brake pressure of the second wheel brake during the pressure increase period. This is advantageous for noise generation and pedal feedback action.

The structure of the brake device disclosed in claim 4 includes a so-called TT distributed brake circuit. That is, both wheel brakes of the brake circuit are assigned to two wheels of one axle. As a result, these advantages are also achieved in the second wheel brake, which is capable of skid-controlled and traction-slip-controlled operation, with regard to these operating conditions, a delay-free start of braking and a rapid release of braking.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A hydraulic brake system 10 shown as a first embodiment in FIG. 1 has two brake circuits I and II.
And have. The brake circuits I and II are so-called K distribution circuits. That is, in each brake circuit, two wheels facing each other in a diagonal direction are connected. Further, the brake device 10 includes a skid control and traction slip control device 11.

The brake device 10 has a master brake cylinder 15 which can be operated by a brake pedal 14.
A pressure medium storage container 16 is placed on the master brake cylinder 15. Master brake cylinder 1
The first brake line 17 of the brake circuit I originates from 5. This brake line 17 leads to a first wheel brake 18 which is arranged, for example, on the left front wheel (not shown) of the motor vehicle. The second brake line 19 of the brake circuit I is connected to a second wheel brake 20 which is associated with the rear right wheel (not shown). The brake circuit II has a first brake conduit 21 to which a wheel brake 22 associated with the driven right front wheel (not shown) of the motor vehicle is connected.
The second brake line 23 of the brake circuit II leads to a wheel brake 24 which is associated with the left rear wheel of the motor vehicle (also not shown). Since both brake circuits I and II are of identical construction, only the brake circuit I will be described in detail below.

A first shut-off valve 27 is present in the first brake conduit originating from the master brake cylinder 15. This shut-off valve 27 is a spring-operated passage position 27a.
Is configured as a 2-port 2-position directional control valve having an electromagnetically switchable shutoff position 27b. The first shut-off valve 27 is bypassed by a first bypass conduit 28 having a first check valve 29. The check valve 29 opens from the master brake cylinder 15 toward the wheel brakes 18. Between the shut-off valve 27 with the bypass conduit 28 and the wheel brake 18, the first brake conduit 17 has a first throttling point 30.

The first wheel brake 18 of the brake circuit 1
A first valve device 33 for modulating the brake pressure is assigned to the. The valve device 33 has an inlet valve 34 configured as a 2-port 2-position directional control valve. The inlet valve 3
4 has one spring-actuated passage position 34a and one electromagnetically switched shut-off position 34b. The inlet valve 34 is bypassed by a second bypass conduit 35 having a second check valve 36. The check valve 36 has a passage direction from the wheel brake 18 to the master brake cylinder 15. The second bypass conduit 35 is connected to the brake conduit 17 on the master brake cylinder side between the first shutoff valve 27 and the first throttle point 30. The other end of the bypass conduit 35 is connected to the inlet valve 34 of the first valve device 33.
And a wheel brake 18 are connected to the brake conduit 17.

From the first brake conduit 17 the inlet valve 3
Between 4 and the wheel brake 18, a return conduit 39 with the outlet valve 40 of the first valve device 33 branches. The outlet valve 40 is constructed as a two-port two-position directional control valve having a spring-actuated shut-off position 40a and an electromagnetically switchable passage position 40b. The return conduit 39 is connected to the suction side of a high-pressure pump 41 configured as an automatic suction type. The high pressure pump 41 is an electric drive motor 4
It can be driven by 2. A pressure medium storage chamber 43 is connected to the return conduit 39. Similarly, on the pump side, the return conduit 3
9, the master cylinder 15 or the pressure medium storage container 1
A suction conduit 44 connected to 6 is connected. From the discharge side of the high-pressure pump 41, the first throttle portion 30 and the first throttle portion 30
A discharge conduit 46, which opens into the first brake conduit 17, branches off from the inlet valve 34 of the valve device 33 of FIG. The discharge conduit 46 has a buffer chamber 47. Brake conduit 17
Includes a first throttle portion 30 and an inlet valve 3 of the first valve device 33.
A third bypass conduit 48 is connected between the four bypass conduits 4 and 4.
The bypass conduit 48 is connected to the second bypass conduit 35 at its master brake cylinder side connection and the second check valve 36.
It is open between and. An outlet valve 61 of the second valve device 55 is arranged in the return conduit branch 60. The outlet valve 61 is configured as a 2-port 2-position directional control valve having a spring-operated shut-off position 61a and an electromagnetically switchable passage position. Furthermore, the brake circuit I comprises a communication conduit 64 which branches from the first brake conduit 17 between the first shutoff valve 27 and the first throttle point 30. The communication conduit 64 opens into the suction conduit 44 between the master brake cylinder 15 and the second shutoff valve 50. A pressure limiting valve 65 having a flow direction from the first brake conduit 17 to the suction conduit 44 is arranged in the communication conduit 64.

An electronic control device 68 belongs to the skid control and traction slip control device 11 of the brake device 10. The control device 68 monitors the rotational state of the wheels (not shown) via the circuit number sensors 69, 70, 71, 72 and, in skid control and traction slip control, corresponds to a predetermined adjustment calculation of the braking device. Some valves and the drive motor 42 are switched.

The multi-circuit braking device has the following functions described using the braking circuit I.

During braking provided by the driver of the motor vehicle, the valve of the braking device 10 is in the position shown and the actuation of the master brake cylinder 15 forces a quantity of pressure medium into the brake conduits 17 and 19 and the wheel brake 18 , 20
At, brake pressure is generated. When a driver desires a fast pressure increase, the front axle wheel brake 1
The transmission of the brake pressure to 8 is effected by the bypass conduits 35 and 48 due to the throttling action of the first throttling point 30. Therefore, the hydraulic brake device 10 has a quick braking start force on the front axle side. When the brake is released, in which the driver reduces the pedaling force applied to the brake pedal 14, the pressure medium amount changes from the wheel brakes 18 and 20 to the brake conduits 17 and 19.
And is returned to the master brake cylinder 15. When the driver depresses the pedal force very quickly, the pressure medium bypasses the first wheel brake 18 and the first throttling point 30 in the first brake conduit 17, through the second bypass conduit 35 and Second from the second wheel brake 20
Second throttle portion 57 of the inlet valve 56 of the valve device 55 of
Is returned to the master brake cylinder 15 through the fourth bypass conduit 58. During such a normal braking operation, the electronic control unit 68 monitors the rotation state of all wheels on the basis of the signals of the rotation speed sensors 69 to 72.

In the event of such braking, if there is a risk of locking the driven wheels, which are assigned to the first wheel brake 18, for example, the control device 68 causes the first valve device 33 to switch to the switching position for increasing the pressure. Switch to. That is, the first
The inlet valve 34 in the brake conduit 17 of the
b and the outlet valve 40 in the return conduit 39 is in the passing position 4
It is switched to 0b. From the wheel brake 18, the pressure medium can flow through the return conduit 39 into the pressure medium storage chamber 43, so that the brake pressure at the wheel brake 18 is reduced. At the same time, the drive motor 42 of the high pressure pump 41 is operated by the control device 68. The high-pressure pump 41 supplies the pressure medium from the wheel brake 18 and from the storage chamber 43 to the discharge conduit 4
6 through the first brake conduit 17 and back to the master brake cylinder 15. In accordance with the regulation program stored in the control device 68, the pressure maintaining period and the pressure increasing period in the wheel brake 18 continue until the driven wheel shows a stable rotating state. In this case, when maintaining the pressure, the inlet valve 34 and the outlet valve 40 of the first valve device 33 are switched to the shutoff position 36b or 40a. When the pressure rises, the outlet valve 40 takes the shut-off position 40a, and the inlet valve 34 switches to the pressure passage position 34a. Pressure medium actuated master brake cylinder 15
From the first brake conduit 17 to the wheel brakes 18 via the bypass conduits 35 and 48.
On the other hand, in the case of skid-controlled operation of the wheel brake 20, the second throttling point 57 in the brake line 19 leads to a decrease in the pressure rise rate. This reduces noise generation when switching the inlet valve 56 and reduces feedback at the brake pedal 14.
At the end of such skid control operation, the control device 68 shuts off the drive motor 42 of the high pressure pump 41. Such a skid control operation is in a corresponding manner all wheel brakes 18, 2 of the braking device 10.
It is possible at 0, 22, 24.

On the other hand, if the wheels assigned to the wheel brakes 18 are exposed to unacceptably large traction slips when starting and accelerating the motor vehicle, this is likewise caused by the control device 68 by the speed sensor 6.
It is detected based on the signals 9 to 72. The control device 68 switches the first shutoff valve 27 to the shutoff position 27b, switches the second shutoff valve 50 to the passage position 50b, and starts the operation of the drive motor 42 of the high-pressure pump 41. At the same time, the inlet valve 56 of the second valve device 55 in the second brake conduit 19 is switched to the shut-off position 56b. The other valves of the braking device 10 remain in the position shown. The high pressure pump 41 transfers the pressure medium from the pressure medium storage container 16 to the master brake cylinder 1
5 and the suction conduit 44. High pressure pump 41
Discharges the pressure medium to the first brake line 17 via the discharge line 46, producing a brake pressure on the wheel brakes 18. This pressure rise process is unthrottled and takes place in the desired manner and at a high pressure rise rate. Even in the traction control operation according to a predetermined adjustment program, the pressure maintaining period and the pressure decreasing period continue during the pressure increasing period.
In this case, the first valve device 33 assigned to the wheel brake 18 assumes the switching position already mentioned during skid control operation. The pressure medium prepared by the pump 41 in such a traction slip control operation but not taken out from the wheel brake 18 is controlled to flow out to the suction conduit 44 through the communication conduit 64 and the pressure limiting valve 65. Such a traction slip control operation has the same form as the brake circuit I.
It is also possible with the I wheel brake 22.

Unlike the above-described first embodiment, the structure of the hydraulic brake device 10 can be simplified by omitting the throttle portion 57 in the second brake conduit 19.

The embodiment shown in FIG. 2 is a hydraulic brake system having TT distribution type brake circuits I and II, that is, the brake circuit I is assigned to the rear axle and the brake circuit II is not activated. It is a hydraulic brake device assigned to the front axle. In the following description of this brake device, the same reference numerals are used for the members shown in FIG.

The brake circuit 1 of the hydraulic brake device 10 of FIG. 2 has a skid control and traction slip control device 11, which enables skid control operation in the brake circuits I and II and additionally in the brake circuit 1. Traction slip control operation is also possible.
The following description will be given only for the brake circuit 1 relevant to the present invention.

A brake circuit I capable of operating the wheel brakes 18 and 20 assigned to the driven rear wheels is almost the same as the brake circuit I of the first embodiment.

The difference between the brake circuit I of the first embodiment and the brake circuit I of the second embodiment is that the wheel brake 20 is used.
A second brake conduit 19 assigned to the first brake conduit 17 branches from the first brake conduit 17 between the throttle point 30 arranged therein and the inlet valve 56 of the first valve device 33. On the other hand, a fourth bypass conduit 58, which bypasses the inlet valve 56 of the second valve device 55 and which has a fifth check valve 59, is provided on the master brake cylinder side of the second check valve 36 on the second side. It is in contact with the bypass conduit 35. Furthermore, the throttle valve is not assigned to the inlet valve 56 of the second valve device 55. With both wheel brakes 18, 20 of the brake circuit 1, the same type of operation as described in connection with the brake circuit I in the first embodiment is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a brake device of the present invention.

FIG. 2 is a diagram showing a second embodiment of the brake device of the present invention.

[Explanation of Codes] 10 Brake Device, 11 Skid Control and Traction Slip Control Device, 14
Brake pedal, 15 master brake cylinder,
17 brake conduits, 18 wheel brakes, 19
Brake conduit, 20 wheel brake, 21 brake conduit, 22 wheel brake, 23 brake conduit,
24 wheel brakes, 27 shutoff valves, 28 bypass conduits, 29 check valves, 30 throttling points, 33
Valve device, 34 inlet valve, 35 bypass conduit, 36
Check valve, 39 return conduit, 40 outlet valve, 41
High-pressure pump, 42 drive motor, 43 pressure medium storage chamber, 44 suction conduit, 46 discharge conduit, 47
Buffer chamber, 48 bypass conduit, 49 check valve, 5
0 shutoff valve, 51 check valve, 55 valve device, 56
Inlet valve, throttling point, 58 bypass conduit, 59
Check valve, 60 return conduit branch, 61 outlet valve,
64 communication conduit, 65 pressure limiting valve, 68 control device, 69, 70, 71, 72 rotation speed sensor

Claims (4)

[Claims] 1. A hydraulic brake system having a skid control and a traction slip control system, comprising: (a) a pedal-operable master brake cylinder (15) to a brake conduit (17) of one brake circuit (I). Leading to one wheel brake (18),
(B) A valve device (33) for modulating a brake pressure is assigned to the wheel brake (18), and the valve device (33) is arranged in the brake device (17) to have an inlet valve (34) and an outlet. (C) A first cutoff valve (27) is arranged on the master brake cylinder side in the (c) brake conduit (17), and the cutoff valve (27) has a traction slip. Shut-off position (27
b), and (d) the first shutoff valve (2)
7) is bypassed by means of a first bypass conduit (28) having a first check valve (29) flowing a pressure medium from the master brake cylinder (15) to the wheel brakes (18), the (e) inlet A second valve (34) flows pressure medium from the wheel brake (18) to the master brake cylinder (15).
Second bypass conduit (35) with check valve (36) of
(F) The high pressure pump (41) is bypassed by the master brake cylinder (15) and the first shutoff valve (27).
A suction conduit (44) between the brake conduit (1
7) and a first shutoff valve (27) and an inlet valve (3)
4) to the brake conduit (1) by the discharge conduit (46)
7), and (g) the high-pressure pump (41) is connected on the suction side by the return conduit (39) to the outlet valve (40) of the valve device (33), and (h) the suction conduit (4).
The second shut-off valve (50) is arranged in 4), the shut-off valve (50) is provided with one shut-off position (50a) and one flow-through position (50b). (4
A buffer chamber (47) and a throttling part (30) in the discharge conduit (46) are arranged on the discharge side behind 1),
(E) A third check valve (49) having a third check valve (49) for flowing a pressure medium from the master brake cylinder (15) to the wheel brakes (18) is provided in the brake conduit (17). (3) In the type in which the third bypass conduit (48) is connected, (le) throttling point (30)
Between the first shutoff valve (27) and the connection of the discharge conduit (46) to the brake conduit (17).
7), the bypass conduit (35) of the inlet valve (34) is at least indirectly throttled (30).
And a first shutoff valve (27) between the brake conduit (17)
A third bypass conduit (48) connected to
On the one hand between the inlet valve (34) of the valve device (33) and the throttle point (30) and on the other hand at least indirectly between the throttle point (30) and the first shut-off valve (27). Hydraulic brake device with skid control and traction slip control device, characterized in that it is connected to a conduit (17). 2. A hydraulic brake system according to claim 1, wherein the shutoff valve (50) of the suction conduit (44) is spring-operated to assume the shutoff position (50a) except during traction slip control operation. 3. A second wheel brake (20) of the brake circuit (I) from the first brake conduit (17) between the master brake cylinder (15) and the shutoff valve (27).
A second brake conduit (19) leading to
A second wheel brake (20) in the brake conduit (19)
A second valve arrangement (5 for modulation of brake pressure at
The inlet valve (56) of 5) and the throttling part (57) are arranged, and the check valve (5) of the second valve device (55) is opened toward the master brake cylinder (15). 5
2. Hydraulic brake system according to claim 1, which is bypassed by a bypass conduit (58) with 9). 4. From the first brake conduit (17) between a throttle point (30) arranged in the brake conduit (17) and the inlet valve (34) of the first valve device (33). A second brake conduit (19) leading to the second wheel brake (20) of the brake circuit (I) is branched, in which the brake pressure in the second wheel brake is modulated. Inlet valve (5) of the second valve device (55)
6) is arranged and the bypass conduit (58) of this inlet valve (56) has a check valve (59) which opens towards the master brake cylinder (15), the first valve arrangement (33)
2. The hydraulic brake system as claimed in claim 1, which is connected to the bypass conduit (35) of the inlet valve (34) of the valve.